The clinical picture was characterized by progressive cognitive dysfunction, behavioral abnormalities, ataxia, and myoclonic jerks. These findings, combined with the EEG demonstrating 1-per-second periodic sharp wave complexes superimposed on a slow background, were highly suggestive of Creutzfeldt-Jakob disease.
Periodic sharp wave complexes (PSWCs) are considered characteristic of sporadic Creutzfeldt-Jakob disease and have a sensitivity and specificity of 67% and 87%, respectively, on a single EEG; however, if repeated recordings are obtained, more than 90% of patients with sporadic Creutzfeldt-Jakob disease show PSWCs. PSWCs on the EEG usually indicate a progressive stage of Creutzfeldt-Jakob disease. They typically become obvious around 8-12 weeks after the onset of clinical symptoms; later onset has been reported in a few cases. PSWCs also occasionally occur in cases of familial Creutzfeldt-Jakob disease and variant Creutzfeldt-Jakob disease, but are absent in cases of iatrogenic human growth factor hormone–related Creutzfeldt-Jakob disease, fatal familial insomnia, and Gerstmann-Sträussler-Scheinker syndrome, which are other types of human-transmissible spongiform encephalopathies. The CSF of this patient also showed elevated levels of neuron-specific enolase, which has been recognized as a neurochemical marker for Creutzfeldt-Jakob disease in the appropriate clinical setting.
Creutzfeldt-Jakob disease is a subacute progressive neurologic disorder caused by the deposition of prion proteins in the brain. Most cases are sporadic; however, some cases are familial and are caused by mutations in the prion protein gene. Prion protein (PrP) is necessary for the normal transmission of electrical impulses between nerves (synaptic function). Prion disease may result when there is generation of PrPSc, an abnormal prion, which leads to progressive loss of functional PrP (PrPc). The normal prion protein undergoes a conformational change into the abnormal prion protein. These abnormal proteins clump together into protein aggregates which lead to neuronal loss.
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Cite this: Sridharan Ramaratnam. A 60-Year-Old Woman With Worsening Neuropsychiatric Symptoms - Medscape - Aug 12, 2015.